A case of canine intoxication and fatality with the pyrethroid insecticide bifenthrin is described. A 5-year-old female spayed Pit Bull Terrier was off leash and unsupervised at home for 15-20 min prior to discovery by her owner. The patient was in lateral recumbency, having what the owner described as a seizure. The patient was transported to an emergency veterinary hospital where she presented with tachycardia, tachypnea and intractable tremors/seizures. Despite aggressive medical intervention, the patient went into respiratory and cardiac arrest and died at 28 h after presentation. A postmortem liver sample screened positive for bifenthrin by gas chromatography-mass spectrometry (GC-MS). During the screening procedure, four additional bifenthrin-metabolic products were also observed. Concentrations for bifenthrin were determined for fat, kidney, liver and urine by GC-MS-MS. This is the first reported case of a canine fatality resulting from bifenthrin.